Dublin District Court heard he had failed to pay the rest despite being given more than a year by a judge.
Fennell is already awaiting the outcome of an assault case after he was found guilty of assault causing harm to his ex-partner, Ashley Carey.
The court heard he had agreed to pay the outstanding €937 back to the State at a rate of €24 per week. Fennell said the money had been coming out of illness benefits he was getting but these payments ceased and he did not notice the repayments were no longer being made.
He said he had made arrangements now to pay the money back and was waiting for the sale of his jointly owned home with Ms Carey to come through.
Judge Victor Blake adjourned the case for a month and said he wanted to see proof of a contract for the sale of the house at Oak Rise, Clondalkin.
Last week, Judge Bridget Reilly ordered a community service suitability report on Fennell, when he was found guilty of smashing Ms Carey's face into the kitchen floor and sitting on her after he claimed she had been "winding him up" at the house in an incident on February 18, 2007.